Applegate T J, Lilburn M S
Department of Animal Sciences, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691, USA.
Poult Sci. 1998 Mar;77(3):433-8. doi: 10.1093/ps/77.3.433.
Turkeys from two BW groups (which averaged 11.8 and 12.9 kg, Normal and Heavy, respectively) were photostimulated at either 29 or 31 wk of age to determine what effects age-associated changes in hen carcass characteristics, egg weight, and egg components have on subsequent poult weight at hatching during the first 10 wk of production. Carcass measurements were determined from a subsample of hens 3 wk after photostimulation (PS). Subsamples of eggs from each PS age and BW group were selected for yolk and albumen measurements. All other eggs from these hens were individually weighed and incubated at 2-wk intervals during the first 10 wk of lay (4 to 14 wk after PS). All incubated eggs were reweighed at 25 d (transfer) and poults were individually weighed at hatch. Hen BW at PS had no effect on ovarian weight and follicular size or number 3 wk later. Hens photostimulated at 31 wk had 18.7 g heavier ovaries 3 wk after PS than hens photostimulated at 29 wk (P < or = 0.06), primarily due to one additional follicle of > or = 20 mm (P < or = 0.04). During the first 10 wk of lay, egg weight increased 7.8 g, 4.4 g of which was due to increased yolk weight. Eggs from Normal BW hens weighed significantly less than those from Heavy BW hens only when hens were subjected to PS at 29 wk. Egg weight at transfer relative to egg weight at set was significantly increased from hens 4 to 6 wk after PS compared with the four older production ages (6 to 8, 8 to 10, 10 to 12, and 12 to 14 wk after PS). There was a significant increase in poult weight with increasing hen production age but no changes in poult weight relative to egg weight at set. In conclusion, hen BW at PS had minimal effects on egg component weights and subsequent poult weight at hatching.
选取两个体重组（平均体重分别为11.8千克和12.9千克，即正常体重组和重体重组）的火鸡，在29周龄或31周龄时进行光照刺激，以确定母鸡胴体特征、蛋重和蛋成分随年龄的变化对产蛋前10周孵化出的雏鸡体重有何影响。在光照刺激（PS）3周后，从母鸡子样本中测定胴体指标。从每个PS年龄和体重组的鸡蛋子样本中选取用于测定蛋黄和蛋清。这些母鸡产的所有其他鸡蛋在产蛋的前10周（PS后4至14周）每隔2周单独称重并孵化。所有孵化的鸡蛋在25天（转移时）再次称重，雏鸡在孵化时单独称重。PS时母鸡体重对3周后的卵巢重量、卵泡大小或数量没有影响。31周龄接受光照刺激的母鸡在PS后3周的卵巢比29周龄接受光照刺激的母鸡重18.7克（P≤0.06），主要是由于多了一个直径≥20毫米的卵泡（P≤0.04）。在产蛋的前10周，蛋重增加了7.8克，其中4.4克是由于蛋黄重量增加。只有当母鸡在29周龄接受PS时，正常体重母鸡产的蛋才明显比重体重母鸡产的蛋轻。与PS后4至6周的母鸡相比，PS后6至8周、8至10周、10至12周和12至14周这四个较老产蛋期的母鸡，转移时蛋重相对于入孵时蛋重显著增加。随着母鸡产蛋年龄的增加，雏鸡体重显著增加，但雏鸡体重相对于入孵时蛋重没有变化。总之，PS时母鸡体重对蛋成分重量和随后孵化时的雏鸡体重影响极小。
